In Situ metal exsolution induced structural transformation enhances activity of the Pd–Sn catalyst for electrocatalytic ethanol oxidation

Abstract

Pd–Sn intermetallic nanoparticles with the composition Pd_1.5Sn_0.5 were synthesized using a one pot solvothermal process. The structure, composition, and morphology of Pd_1.5Sn_0.5 were characterized by Powder X-ray Diffraction (pXRD), X-ray Photoelectron Spectroscopy (XPS), High-Resolution Transmission Electron Spectroscopy (HRTEM) and X-ray Absorption Spectroscopy (XAS). The electrochemical activity towards the ethanol oxidation reaction (EOR) and durability of the catalyst were tested in an alkaline medium using cyclic voltammetry measurements. The catalyst demonstrated a gradual increase in activity over successive reaction cycles and exhibited better durability compared to the commercial 20 wt% Pd/C catalyst. Post EOR analysis revealed a structural transformation of the catalyst, attributed to the exsolution of Sn atoms from the lattice during the electrochemical process. This process regenerated the Pd-rich catalyst in each cycle, significantly improving its activity and durability, enabling stable performance over 1000 continuous reaction cycles.